The invention relates to angle measuring apparatus for determining the angle a planar surface makes with a cylindrical surface.
In the field of gravure printing, ink is transferred from a reservoir to an engraved cylinder and it is necessary to remove excess ink before contact is made between the ink carrying surface of the cylinder and a record medium. To this end, it is conventional to mount a doctor blade adjacent to the cylinder to removed excess ink and to maintain a constant ink thickness. It has been found that the angle of inclination of the doctor blade to the cylinder critically determines the performance of the printing process and also affects the lifetime of the cylinder. It is therefore desirable to determine this angle.
In the past, the angle has been determined by for example using putty or plasticine but this is very inaccurate.
More accurate, known angle measuring apparatus comprises an elongate support; a horizontal level detecting device pivotally connected to an upper surface of the support; and means for determining the angle between the support and the horizontal level detecting device. Such apparatus is hereinafter referred to as of the kind described.
One example of apparatus of the kind described is the well known clinometer. This is not suitable for determining the inclination angle of a doctor blade to a gravure cylinder in view of the curved form of the cylinder.